Mono-ar-tert-butyl toluenediamine is a known compound useful as a polyurethane chain extender. Burgoyne, et al. U.S. Pat. No. 4,745,223 and U.S. Pat. No. 4,816,543 describe a process for mono-tertbutylating toluenediamine (hereinafter "TDA") using an acidic zeolite catalyst over a very long reaction time.
Stroh, et al. Angew. Chemie, 69, Nr 4, (1957) pp. 124-131describe the ethylation of TDA using aluminum anilide as the catalyst to form almost exclusively ar, ar-diethyl isomers of toluenediamines. (Note: "ar" is a conventional designation for aromatic ring substitution) When aluminum chloride is included with the aluminum anilide as a co-catalyst, the ethylation goes quantitatively to ar, ar-diethyl toluenediamines.
Stroh, et al. also report the butylation of aniline and toluidine with aluminum anilides and with aluminum chloride, montmorillonite or boron trifluoride catalysts but do not describe butylation of aromatic diamines. Similar results are reported in Stroh, et al. U.S. Pat. No. 3,275,690.